The present invention relates to a procedure for manufacturing a chassis for a radio telephone, for attaching circuit boards on the chassis, and a chassis made according to this procedure.
Various radio telephone chassis are known in the art on which the circuit boards of the radio telephone are attached. Such chassis are usually cast or pressed chassis of aluminium provided with thicker points, or `towers`, in which a threaded hole has been made for fixing the circuit board thereon with a screw or threaded bolt to form a screw joint. Similarly, the chassis are provided with `towers` on which the shell components of the apparatus are likewise fixed applying by means of a screw joint, when assembling the radio telephone. The fixing can be carried out self-tapping screws.
Chassis of the type known in the art are subject to certain drawbacks. The aluminium chassis is rather expensive to manufacture, in particular when a cast chassis is used. Drilling and threading the holes for the fixing screws add work steps and consequently, costs. Fixing RF shielding covers and achieving good sealing is also problematic. A radio telephone chassis of the kind known in the art constitutes an entity together with the outer shell intended to be affixed thereto. This implies that since the fixing is done with screw joints, the chassis on which the circuit boards have been attached and the shell must be mutually consistent at the fixing points. Hence, it follows that a particular shell only can be used with a given chassis. Said feature restricts the number of the external modifications of the apparatus. Whenever one desires to produce a radio telephone of novel appearance, it becomes necessary to design a new chassis to go with it.